JP2010272725A - Thin film solar cell module and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin film solar cell module excellent in an effect of relaxing stress by thermal expansion, in which a hollow space hardly occurs between a bus-bar wiring and a collective electrode even when the used bus-bar wiring is wide. <P>SOLUTION: In a connection process of arranging the bus-bar wiring 17 on the collective electrode 22 formed in the thin film solar cell module 10 to connect the wiring 17 to the electrode 22, the collective electrode 22 and the bus-bar wiring 17 are electrically connected to each other at a plurality of connections 13 spaced each other so that a spacer 15 containing thermosetting resin is arranged between the collective electrode 22 and the bus-bar wiring 17 in the spaced region. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a structure of a solar cell module and a manufacturing method thereof.

  A module of a thin-film solar battery cell using amorphous silicon or the like as a power generation layer is configured as in Patent Document 1, for example. A plurality of thin-film solar cells arranged in parallel on the light-transmitting insulating substrate are connected in series to form an integrated thin-film solar cell device. A positive electrode current collector and a negative electrode current collector are formed at one end and the other end of the integrated thin film solar cell device, respectively. The thin-film solar battery is a long and narrow rectangle, and the long side of the rectangle has a length that extends over almost the entire width of the translucent insulating substrate. Between adjacent thin-film solar cells, the transparent electrode film of one cell and the back electrode film of the other cell are connected to each other and connected in series. A linear P-type electrode terminal portion having substantially the same length as the thin-film solar battery cell is formed on the end portion of the transparent electrode film of the thin-film solar battery cell at one end connected in series. Moreover, the same N-type electrode terminal part is formed in the edge part of the back surface electrode film of the thin film photovoltaic cell of the other end. These P-type electrode terminal part and N-type electrode terminal part serve as an electrode extraction part. The P-type electrode terminal portion is electrically and mechanically joined to the entire surface of the P-type electrode terminal portion, which is called a bus bar made of a copper foil having the same shape and size as the terminal portion. Similarly, a negative electrode current collector having the same shape and size as the N-type electrode terminal is bonded to the entire surface of the N-type electrode terminal. Then, on the integrated thin film solar cell device, a positive electrode lead wire and a negative electrode lead wire that cross the thin film solar cell are respectively connected to the positive electrode current collector and the negative electrode current collector. The entire back surface of the integrated thin film solar cell device is laminated and sealed with the other ends of the positive electrode lead wire and the negative electrode lead wire penetrating therethrough. Laminate sealing is performed with a sealing insulating film and a back film.

  In a conventional polycrystalline silicon solar cell module, an interconnector is used for connecting a plurality of solar cells as in Patent Document 2. The interconnector includes electrode contact portions formed of copper foil or the like at both ends, and the entire surface thereof is covered with solder. One electrode contact portion of the interconnector is connected to the bus bar portion of the current collecting electrode on the surface of the solar battery cell, and the other electrode contact portion is connected to the current collecting electrode on the back surface of the adjacent solar battery cell. The connection between the electrode contact portion and the collecting electrode portion is joined by soldering. In order to reduce the resistance loss due to the interconnector, when the surface area is increased, the light receiving area on the surface of the solar battery cell is reduced and the output is reduced. On the other hand, if the thickness of the interconnector is increased in order to prevent this decrease in output, the compressive stress applied from the interconnector to the semiconductor substrate accompanying a temperature change during soldering increases. Therefore, Patent Document 2 proposes a method of connecting an interconnector provided with a concavo-convex portion in advance so that problems due to compressive stress can be prevented even if the interconnector is thickened.

  Patent Document 3 shows a solar cell module in which a solar cell made of a silicon substrate electrically connected to a connection tab is sealed between a translucent surface member and a back surface member. . The connection tab includes a plurality of connection portions that form a connection surface with the solar cell, and a connection portion that separates the connection surface with the solar cell and connects the plurality of connection portions to each other. The length of the connection portion is at least about half of the length in which the connection tab and the solar cell overlap. The solar cell is sealed between the front surface and the back surface member by heating and compressing the laminated body formed by stacking the back surface member, the sealing material sheet, the solar cell connected by the connection tab, the sealing material sheet, and the front surface member. . As the sealing material sheet, a sheet in which a portion corresponding to the connection tab is removed or a film thickness thereof is thinner than other portions is used. Thereby, it is suppressed that a stress is directly applied to the connection tab in the sealing process.

JP 2000-68542 A Japanese Patent Laying-Open No. 2005-302902 (page 13, FIG. 3) Japanese Patent Laid-Open No. 11-312820

  In a thin film solar cell module using a glass substrate as in Patent Document 1, when a bus bar made of copper foil is electrically and mechanically joined to the entire surface of the current collecting electrode, from the difference in thermal expansion between the glass substrate and the copper foil, In a heating process such as resin sealing performed after bonding, a problem occurs in that stress is generated between the collecting electrode and the copper foil and the collecting electrode is peeled off. Further, as in Patent Document 2, when an interconnector provided with an uneven portion in advance is connected, the stress due to the difference in thermal expansion is relieved at the bent portion of the interconnector. However, the collector electrode of the thin-film solar cell module is generally made of a thin metal layer and has a lower mechanical strength than the collector electrode of a polycrystalline silicon solar cell module formed by baking a metal paste or the like. For this reason, when the interconnector which provided the uneven | corrugated | grooved part beforehand is connected like patent document 2, it receives the pressure from a back surface when sealing, and a bending part strongly presses against a current collecting electrode, and the problem which damages a current collecting electrode Occurs. Alternatively, there is a problem that the convex portion is deformed and the effect of relaxing the thermal expansion difference cannot be obtained sufficiently. Like patent document 3, the stress applied to a current collection electrode can be suppressed by using the sheet | seat from which the part corresponding to a bus bar was removed or thinned in the sealing process. However, when the bus bar wiring having a wide width is used, there is a problem that the sealing resin does not enter the gap below the bus bar wiring and the cavity tends to remain. Furthermore, there is a problem that the convex shape of the bus bar wiring is deformed at a portion where the sealing resin does not enter, and the effect of reducing the difference in thermal expansion cannot be obtained sufficiently. Further, when the sealing resin enters the gap below the periphery of the convex portion, there is a problem that the thickness of the sealing resin around the convex portion becomes thin.

  Therefore, the present invention realizes a thin film solar cell module that is excellent in the effect of relieving stress due to thermal expansion and that is less likely to generate a cavity between the bus bar wiring and the collector electrode even when a wide bus bar wiring is used. For the purpose.

  The method for manufacturing a thin film solar cell module according to the present invention includes: a thin film solar cell in which a plurality of thin film solar cell elements and a collecting electrode for extracting electric power to the outside are formed on a translucent substrate. A step of preparing, a connecting step of arranging a bus bar wiring on the current collecting electrode and electrically connecting to the current collecting electrode, and a seal made of a thermoplastic resin on the thin film solar cell and the bus bar wiring. A sealing step of covering and sealing with a stop sheet and a back sheet, and in the connection step, the current collecting electrode and the bus bar wiring are electrically connected by a plurality of connecting portions spaced from each other. In the method for manufacturing a thin-film solar cell module, a spacer containing a thermoplastic resin in the interval region is installed between the current collecting electrode and the bus bar wiring.

  Further, the solar cell module of the present invention is a thin film having a plurality of thin film solar cell elements electrically connected to each other and a collector electrode formed on a part of the thin film solar cell element on a light-transmitting substrate. A solar cell, a bus bar wiring disposed on the current collecting electrode and electrically connected to the current collecting electrode, a back sheet covering the thin film solar cell and the bus bar wiring, the thin film solar cell, and the A sealing adhesive layer made of a thermoplastic resin between the bus bar wiring and the back sheet, and the bus bar wiring is electrically connected to the current collecting electrode at a plurality of connecting portions spaced from each other, Between the connecting portions, there is a connecting portion that is separated from the current collecting electrode by a spacer containing a thermoplastic resin, and the spacer between the connecting portion and the current collecting electrode is lateral to the connecting portion. The part that protrudes And a thin film solar cell module characterized in that it has.

  In the method for manufacturing a thin film solar cell module according to the present invention, the current collecting electrode and the bus bar wiring are electrically connected through a plurality of connecting portions spaced from each other, and a spacer containing a thermoplastic resin is collected in the spacing region. Since it includes being installed between the power electrode and the bus bar wiring, it is possible to easily manufacture a connecting portion that is not fixed to the current collecting electrode and is excellent in the effect of relieving the stress due to the difference in thermal expansion. Further, even if the bus bar wiring is a wide foil or thin plate, the thermoplastic resin is easily filled between the current collector electrodes, and cavities are not easily generated. Furthermore, even when pressure is applied from the backsheet side, since the spacer containing the thermoplastic resin is located between the bus bar wiring and the current collecting electrode, the pressure applied to the current collecting electrode through the connecting portion is reduced and the current collecting is reduced. Damage to the electrode can be prevented.

  In the thin film solar cell module of the present invention, the bus bar wiring is electrically connected to the current collecting electrode at a plurality of connecting portions spaced from each other, and a thermoplastic resin is interposed between the current collecting electrodes between the connecting portions. It has the connection part separated by the resin spacer to contain, and has the part which the resin spacer between a connection part and a current collection electrode protrudes to the side of a connection part. Thereby, it becomes a structure where the thickness of the thermoplastic resin layer between the back sheet and thin film solar cell in the side of a connection part is thicker than a sealing contact bonding layer. Thus, since the thermoplastic resin layer on the side of the connecting portion of the bus bar wiring is thick, the connecting portion is excellent in the effect of relieving stress due to thermal expansion.

It is a perspective view which shows the structure of the thin film solar cell used for the thin film solar cell module of Embodiment 1 of this invention. It is the disassembled perspective view which looked at the thin film solar cell module of Embodiment 1 of this invention from the back side. It is the perspective view which looked at the thin film solar cell module of Embodiment 1 of this invention from the back side. It is the top view and sectional drawing explaining the manufacturing process of the thin film solar cell module of Embodiment 1 of this invention. It is the top view and sectional drawing explaining the manufacturing process of the thin film solar cell module of Embodiment 1 of this invention. It is the top view and sectional drawing explaining the manufacturing process of the thin film solar cell module of Embodiment 1 of this invention. It is sectional drawing explaining the manufacturing process of the thin film solar cell module of Embodiment 1 of this invention. It is sectional drawing explaining the manufacturing process of the thin film solar cell module of Embodiment 1 of this invention. It is sectional drawing explaining the partial structure of the thin film solar cell module of Embodiment 1 of this invention. It is sectional drawing explaining the partial structure of the thin film solar cell module of Embodiment 1 of this invention. It is sectional drawing explaining the manufacturing process of the thin film solar cell module of Embodiment 2 of this invention. It is sectional drawing explaining the manufacturing process of the thin film solar cell module of Embodiment 3 of this invention. It is sectional drawing explaining the partial structure of the thin film solar cell module of Embodiment 3 of this invention. It is the top view and sectional drawing explaining the manufacturing process of the thin film solar cell module of Embodiment 4 of this invention. It is sectional drawing explaining the manufacturing process of the thin film solar cell module of Embodiment 5 of this invention. It is the top view and sectional drawing explaining the manufacturing process of the thin film solar cell module of Embodiment 6 of this invention. It is the top view and sectional drawing explaining the manufacturing process of the thin film solar cell module of Embodiment 7 of this invention. It is the top view and sectional drawing explaining the manufacturing process of the thin film solar cell module of Embodiment 8 of this invention. It is sectional drawing which shows the top view explaining the manufacturing process of the thin film solar cell module of Embodiment 9 of this invention, and the structure of a finished product. It is sectional drawing which shows the top view explaining the manufacturing process of the thin film solar cell module of Embodiment 10 of this invention, and the partial structure of a finished product.

<Embodiment 1. >
FIG. 1 is a perspective view showing the structure of a thin film solar cell used in the thin film solar cell module of the first embodiment. Sunlight is a thin film solar cell that enters from the substrate side, and the figure is a view from the back side where the thin film solar cell element is formed. FIG. 2 is an exploded perspective view of the first embodiment thin film solar cell module as seen from the back side. FIG. 3 is a perspective view of the first embodiment thin film solar cell module as seen from the back side, and is a completed view assembled from the exploded perspective view of FIG.

A thin film solar cell 100 in FIG. 1 is an integrated solar cell in which a plurality of thin film solar cell elements 10 electrically connected to each other are disposed on a rectangular translucent substrate 1 such as glass. The thin film solar cell element 10 is a narrow rectangle, and its long side is parallel to one side of the translucent substrate 1. A plurality of thin film solar cell elements 10 are arranged in a direction perpendicular to the long side. In the thin film solar cell element 10, the transparent electrode 2, the photoelectric conversion layer 4, and the back electrode 6 are laminated in this order from the substrate side. The transparent electrode 2 is made of an oxide transparent conductive material such as SnO ₂ , ZnO, or ITO. The photoelectric conversion layer 4 is made of an amorphous silicon film, a microcrystalline silicon film, or the like. The back electrode 6 is made of a metal material such as silver or aluminum. A groove in which the photoelectric conversion layer 4 is divided is formed between adjacent thin-film solar cell elements 10, and the transparent electrode 2 of one element and the back electrode 6 of the other element are electrically connected in series in the groove. .

  The typical size and shape of each element is, for example, that the size of the translucent substrate 1 is a rectangle having a length of 150 cm and a width of 100 cm, and the thin-film solar cell element 10 is a rectangle having a length of 140 to 149 cm and a width of 0.5 to 2 cm. It is. About several 10 to 200 elements of the thin film solar cell element 10 are connected to each other. The thickness of each layer constituting the element is, for example, 0.2 to 1 μm for the transparent electrode 2, 0.2 to 5 μm for the photoelectric conversion layer 4, and 0.2 to 3 μm for the back electrode 6.

  Current collecting electrodes 21 and 22 for taking out electric power to the outside are formed in a part of the thin film solar cell elements 10 connected to each other. The figure shows a structure in which the back electrode 6 on the thin film solar cell element 10 located in the vicinity of the edge of the substrate is the collecting electrodes 21 and 22. A conductive film connected to the back surface electrode 6 and the transparent electrode 2 of the thin film solar cell elements 10 at both ends arranged may be formed in the peripheral portion of the translucent substrate 1, and these may be used as current collecting electrodes 21 and 22.

  As shown in FIG. 2, in the thin film solar cell module according to the first embodiment, the spacer 15 and the bus bar wiring 17 are installed on the current collecting electrodes 21 and 22 of both electrodes. A lead wire 23 is installed on the bus bar wiring 17 so that one end thereof is connected. An electrically insulating resin sheet 24 is sandwiched between the lead wire 23 and the back electrode 6 of the thin-film solar cell element 10. The other end of the lead wire 23 is located near the center of the substrate. Above these, the entire back surface of the thin film solar cell 100 is covered with a sealing sheet 25 and a back sheet 27. Openings are formed in the sealing sheet 25 and the back sheet 27 so that the other end of the lead wire 23 is exposed near the center of the substrate. A connection box 31 is installed on the back sheet 27 so as to cover the opening. As shown in FIG. 3, the completed module after stacking has a structure in which the entire back surface is covered with a back sheet 27 and a connection box 31 is installed in a part thereof. The connection box 31 seals the opening, and the other end of the lead wire 23 and an external wiring (not shown) are connected therein. Electric power is taken out from the module by external wiring. The bus bar wiring 17 is an intermediate member that makes it easy to connect the power of the wide thin-film solar electronic element 10 to the lead wire 23 with low loss.

  The connection between the current collecting electrodes 21 and 22 and the bus bar wiring 17 may not be 1: 1. For example, the bus bar wiring 17 may be divided into two or more in the direction along the current collecting electrodes 21 and 22, and a plurality of current collecting electrodes and the bus bar wiring 17 may be connected.

  For the sealing sheet 25, for example, a thermoplastic resin material having a melting point of about 70 to 100 ° C. can be used. When a material mainly composed of EVA is used as the material, adhesion and flexibility are good, and the thin film solar cell element 10 is excellent in protection.

  The back sheet 27 is a member that mechanically and electrically protects the inside of the solar cell for a long period of time and prevents corrosion due to humidity or the like. Also called back film. As the material, it is preferable to use a material that has good mechanical strength, electrical insulation, moisture resistance, and high adhesion to the sealing sheet. For example, as the material, a polyvinyl fluoride resin (PVF) film, a polyethylene terephthalate (PET) film, and a film in which an aluminum layer is laminated to improve moisture resistance may be used. Moreover, you may use what laminated | stacked the sealing resin sheet and the back sheet | seat integrally.

  As shown in FIG. 2, the current collecting electrodes 21 and 22 and the bus bar wiring 17 are electrically connected by a plurality of connecting portions 13 spaced apart from each other. The plurality of connection portions 13 form a row along the direction in which the current collecting electrodes 21 and 22 and the bus bar wiring 17 extend. A sheet-like spacer 15 is sandwiched between the collector electrodes 21 and 22 and the bus bar wiring 17 between the adjacent connection portions 13 in these rows. The figure shows that the tooth portion of the comb-shaped spacer 15 is installed in the region between the adjacent connecting portions 13. In this case, the connection portions 13 and the spacers 15 are alternately arranged in the direction in which the current collecting electrodes 21 and 22 extend.

  The bus bar wiring 17 is made of a thin metal material such as a copper foil having a thickness of 30 to 200 μm, for example. When the current collecting electrodes 21 and 22 extend along the sides of the substrate as shown in the figure, the bus bar wiring 17 also has a belt-like shape along the direction in which the current collecting electrodes 21 and 22 extend. Good. It is preferably thin so that it can be deformed relatively easily by pressing. A typical bus bar wiring 17 has a tape shape having a width of about 5 mm and a thickness of 0.03 to 0.1 mm. Further, it may be formed of a flat wiring material (a metal such as Au, Ag, Cu, Al, Ti, or an alloy thereof), and the surface may be plated with a bonding metal material or the like. It is preferable to make the width narrower than the widths of the collecting electrodes 21 and 22 so as not to short-circuit the back electrode 6 of the adjacent thin film solar cell element 10.

  As a connection material for electrically and mechanically connecting the current collecting electrodes 21 and 22 and the bus bar wiring 17 in the connection portion 13, a conductive adhesive, a low melting point metal, a conductive adhesive film, or the like can be used. When a film of a connection material is formed on the bus bar wiring 17 in advance by plating or the like, the film may be used. The space | interval of the adjacent connection part 13 can be 1-15 cm etc., for example. Further, the shape and size of the connecting portion 13 may be, for example, a square having a side of 0.1 to 2 cm and a circle having a diameter of 0.1 to 2 cm. It is preferable to reduce the size compared to the interval between the connecting portions 13. You may change the shape of the adjacent connection part 13 or make those intervals non-uniform | heterogenous. These sizes and shapes may be appropriate sizes and shapes according to the voltage and current generated by the thin film solar cell 100, the properties of the material of the connection portion 13, and the like. The connection portion 13 may have a bump shape protruding from the current collecting electrodes 21 and 22.

  The sheet-like spacer 15 is located almost entirely or partially in the region between the adjacent connecting portions 13. When the interval between the connecting portions 13 is sufficiently larger than the size of the connecting portion 13, the spacer 15 may occupy at least half of the interval. It is further preferable that a gap of about 0.5 to 5 mm is left between the spacer 15 and the connection portion 13 so that the entire space between the other connection portions is covered with the spacer 15.

  The thickness of the spacer 15 is desirably thicker than the thickness of the connection material in the connection portion 13. For example, when the thickness of the connection material is 30 to 40 μm, the thickness of the spacer 15 is preferably sufficiently thick, for example, 0.1 to 1 mm. The thickness of the spacer 15 is preferably 0.5 mm or more than the thickness of the connection material. If the thickness of the connecting material is 0.1 mm or less, a material with a thickness of about 0.6 to 0.8 mm may be used.

  The material of the spacer 15 is made of an insulating resin material, and is particularly preferably made of a thermoplastic resin material. A thermoplastic resin material is an excellent material that retains flexibility even when it is once heated and melted and solidifies again at a low temperature. For example, ethylene vinyl acetate copolymer (EVA) is suitable as the material. A material based on an olefin resin that generates less acid gas may also be used. More preferably, it is made of a thermoplastic resin material having the same quality as the sealing sheet 25. A material obtained by combining these thermoplastic resin materials and other materials may also be used. A composite material in which EVA and a polyethylene terephthalate (PET) film are laminated may be used. As long as the material contains a thermoplastic resin material, an inorganic material such as metal or ceramics may be mixed in part.

  Moreover, the shape of the sheet-like spacer 15 is good to have a side surface perpendicular | vertical to the direction where the bus-bar wiring 17 which faces the adjacent connection part 13 side extends. For example, a rectangular spacer 15 having both side surfaces parallel to each other is installed such that both side surfaces vertically cross the bus bar wiring 17. For example, as shown in FIG. 2, the comb teeth of the comb-shaped spacer 15 extending in the direction perpendicular to the extending direction of the current collecting electrodes 21 and 22 may be inserted between the connecting portions 13. The comb teeth have side surfaces perpendicular to the extending direction of the collecting electrodes 21 and 22.

  The spacer 15 may have a portion that protrudes between the current collecting electrodes 21 and 22 and the bus bar wiring 17. Furthermore, it is good to make it the shape where the some pattern used as a spacer was connected continuously by the part which protrudes. In FIG. 2, a comb-shaped portion of the comb-shaped spacer 15 is a spacer sandwiched between adjacent connecting portions 13, and a comb-shaped base portion is integrated by connecting the spacers. Further, when the end portion side of the substrate is narrow, the connecting portion is preferably located closer to the center of the translucent substrate 1 than the collecting electrodes 21 and 22 as shown in the figure. A fine slit or a fine uneven pattern may be formed on a part of the surface of the spacer 15 between the connecting parts.

  The back sheet 27 is preferably made of a material that has good mechanical strength, electrical insulation, moisture resistance, and high adhesion to the sealing sheet. For example, as the material, a polyvinyl fluoride resin (PVF) film, a polyethylene terephthalate (PET) film, and a film in which an aluminum layer is laminated to improve moisture resistance may be used. Moreover, you may use what laminated | stacked the sealing resin sheet and the back sheet | seat integrally.

  Next, a procedure for manufacturing the thin film solar cell module of the first embodiment will be described. 4 to 8 are top views or cross-sectional views for explaining a manufacturing process of the thin film solar cell module according to the first embodiment. These are enlarged views of the region where the collecting electrode 22 is formed at the periphery of the solar cell panel indicated by the dotted line Y1Y2 or X1X2 in FIG.

  First, in a manufacturing process, the thin film solar cell 100 in which the collector electrodes 21 and 22 which take out electric power to the exterior in the some thin film solar cell element 10 and some thin film solar cell elements 10 were formed on the translucent board | substrate 1 is used. prepare.

This thin-film solar cell 100 includes a transparent electrode 2 made of an oxide transparent conductive material such as indium tin oxide (ITO) and tin oxide (SnO ₂ ), an amorphous silicon film, and a fine film on a transparent substrate 1 such as glass. The photoelectric conversion layer 4 made of a crystalline silicon film or the like and the back electrode 6 made of a metal material such as silver or aluminum are sequentially laminated by a CVD method or a sputtering method. The back electrode 6 may be made of a metal such as Ag, Al, or Ti, or a metal compound. A film having a thickness of 1 μm or less can be formed by vacuum deposition, reactive sputtering, or the like. Separation grooves 9 are formed in these layers by a method such as laser scribing in the middle of lamination or after lamination. The laminated film is divided into a plurality of elongate solar cell elements 10 by the separation grooves 9. Further, the photoelectric conversion layer 4 and the back electrode 6 of the solar cell elements 10 adjacent in the separation groove 9 are electrically connected in series.

  FIG. 4 (a) is a top view of the peripheral portion of the substrate of the thin-film solar cell module according to Embodiment 1 viewed from the back side in the middle of the manufacturing process, and FIG. 4 (b) is a cross-sectional view thereof. The back electrode 6 of the thin film solar cell element 10 located at the end of the translucent substrate 1 is used as the current collecting electrode 22. A process for forming the collector electrode 22 is not required separately, and the process is simplified.

  The conductive connection material 12 is installed at a plurality of locations spaced apart on the current collecting electrode 22. This connection material 12 becomes the connection portion 13. The collector electrode 22 has an elongated shape along the side of the substrate, and a plurality of connection materials 12 are arranged in the extending direction so as to form a row with a gap G therebetween. The width C1 of the connecting material 12 in the extending direction may be smaller than the distance G. The width C2 of the connection material 12 in the direction orthogonal to the extending direction is made smaller than the width of the current collecting electrode 22. The connecting material 12 is placed at a distance from the separation groove 9 so as not to contact the back electrode 6 of the adjacent solar cell element 10.

  The connection material 12 is, for example, an adhesive tape in which conductive particles are dispersed, an anisotropic conductive film, a conductive paste, or the like. FIG. 4B is a cross-sectional view in which these are arranged on the collecting electrode 22. The period P of the connecting material 12 arranged in the extending direction does not necessarily have to be constant in the extending direction. The thickness of the connecting material 12 is 30 to 100 μm or the like for a film member, and about 50 to 250 μm for a conductive paste. When a film member is used, a connection portion shape with a certain film thickness may be obtained. In the case of a conductive paste, it may be formed by a method such as screen printing. As these typical sizes, the width C1 of the connecting portion 13 in the direction in which the current collecting electrode 22 extends is 1 to 20 mm, the interval G in the extending direction is 20 to 150 mm, and the connecting material 12 in the direction perpendicular thereto The width C2 is 1 to 8 mm, and the width W of the collecting electrode 22 is 5 to 10 mm. Further, if a connection material is attached to the surface of the bus bar wiring 17, the connection material 12 does not necessarily have to be installed on the current collecting electrode 22 side.

  Next, a sheet-like spacer 15 is placed in a region between adjacent connection materials 12. The top view of FIG. 5A and the cross-sectional view of FIG. 5B show a state where the spacer 15 is placed on FIGS. 4A and 4B, respectively. The spacer 15 has a thermoplastic resin material on the surface. For example, as shown in FIG. 5A, rectangular patterns having a width E1 and a length E2 are arranged in parallel at intervals, and one side of each rectangle is connected by a pattern having a width E3. This shape can be regarded as a comb shape having a rectangular pattern portion as a tooth and a pattern having a width E3 as a base. The base of the comb was installed closer to the center of the translucent substrate 1 than the connecting portion 13 and protruded from the back electrode 6 of the adjacent solar cell element. There was a slight gap between the connecting portion 13 and the rectangular tooth pattern. Further, as shown in the sectional view of FIG. 5B, a sheet-like spacer 15 thicker than the thickness of the connection material 12 was used.

  Next, the bus bar electrode 17 is placed on the spacer 15 and the connection material 12. The top view of FIG. 6A and the cross-sectional view of FIG. 6B are views showing a state where the bus bar electrode 17 is placed on FIGS. 5A and 5B, respectively. The width W of the bus bar electrode 17 is slightly narrower than the width of the current collecting electrode 22. For example, the width M of the current collecting electrode 22 is 5 to 10 mm, and the width M is 3 to 8 mm so that the current does not protrude from the upper surface of the adjacent solar cell element 10 from above the current collecting electrode 22. . Further, it is more preferable that a part of the spacer 15 protrudes from the side surface of the bus bar electrode 17 as shown in FIG. The bus bar electrode 17 can be easily formed by cutting a metal tape such as copper or copper alloy having a thickness of 30 to 100 μm.

  Next, as indicated by the white arrow in FIG. 6B, the bus bar electrode 17 on the connection material 12 is pressed toward the substrate side to contact the bus bar electrode 17 and the connection material 12 to be electrically and mechanically connected. A connecting portion 13 is formed. The connecting portion 13 may be formed in order from one end of the bus bar electrode 17. By connecting in order from one side, the other side of the bus bar electrode 17 becomes a free end in the middle stage. The bus bar electrode 17 is slightly bent because the height is different between the spacer 15 and the connecting material 12, but the length of the bent portion can be compensated by the movement of the free end, so that stress hardly remains in the bus bar electrode 17. Further, if the bus bar electrode 17 is a material having a high ductility, the plurality of connection portions 13 may be pressed at the same time so that the bus bar electrodes 17 are slightly extended at the bent portions. Alternatively, the bus bar electrode 17 may be placed in a slightly slackened state, and similarly, a plurality of connection portions 13 may be pressed at the same time for connection. It is sufficient that the processing speed can be increased by connecting a plurality of locations simultaneously. Further, when the bus bar electrode 17 is very thin and bends by its own weight and comes into contact with the connection material 12, pressing is not necessarily required.

  In the case where the connection material 12 is a conductive film such as ACF (Anisotropic Conductive Film), it is cut into several mm squares and bonded onto the current collecting electrode 22 in advance. Connection processing is performed by simultaneously applying pressure and heat from the back side of the bus bar electrode 17. Processing may be performed one by one while the bus bar electrode 17 is placed on the collecting electrode 22. The heat treatment temperature varies depending on the type of resin constituting the ACF, but is generally 200 ° C. or lower.

  When the connection material 12 is a conductive adhesive, it is applied in advance on the current collecting electrode 22 using a dispenser or the like. After the bus bar electrode 17 is placed thereon, heat treatment is performed using an oven or the like, thereby forming an electrical connection between the back electrode and the bus bar wiring.

  When the connection material 12 is solder, the solder is applied on the current collecting electrode 22 in advance. When the bus bar electrode 17 is placed on the bus bar electrode 17, the applied solder is melted one by one to form a joint between the bus bar wiring 17 and the current collecting electrode 22. If a multi-head mass production machine is used, simultaneous multi-point processing is possible.

  The connecting step of arranging the bus bar wiring 17 on the current collecting electrode 22 and electrically connecting to the current collecting electrode 22 can be performed in various orders other than the procedure described above. The connecting material 12 may be installed after the spacer 15 is installed first. Further, a connection material or a spacer 15 may be pasted on the bus bar electrode 17 side in advance. The current collecting electrode 22 and the bus bar wiring 17 are electrically connected by a plurality of connecting portions 13 spaced apart from each other, and a spacer 15 containing a thermoplastic resin is provided in the space region of the connecting portion 13 between the current collecting electrode 22 and the bus bar. What is necessary is just to make it install between wiring 17. Through these connection processes, a connecting portion is formed in the bus bar wiring 17 to electrically connect the adjacent connecting portions 13 apart from the current collecting electrodes 22. Further, in the above procedure, the bus bar wiring 17 having irregularities formed in advance is not directly connected to the current collecting electrode 22, and the bus bar wiring 17 is first placed on the spacer 15 and then connected to the current collecting electrode 22. . Since only the bent portion of the bus bar wiring 17 does not hit the collecting electrode 22 locally, the collecting electrode 22 is not easily damaged.

  Next, the thin film solar cell 100 and the bus bar wiring 17 are covered with a sealing sheet 25 made of a thermoplastic resin and a back sheet 27. The cross-sectional view of FIG. 7 shows that the top after the connection step of FIG. 6B is covered with the sealing sheet 25 and the back sheet 27. As shown in FIG. 7, the bus bar wiring 17 after the connection process becomes uneven due to the difference in height between the spacer 15 and the connection portion 13. In addition, although the connection part 13 consists of the connection material 12, it may become lower than the height of the connection material 12 by pressing. The top of the spacer 15 is generally flat, and an inclined portion that is bent is formed in a gap portion between the spacer 15 and the connection portion 13. The connecting portion mainly includes a flat portion and an inclined portion, and has a gentle mountain shape as a whole.

  8 is a cross-sectional view in the vertical direction of FIG. 7 and corresponds to a position between dotted lines X1X2 in FIG. This figure also shows a portion where the spacer 15 is sandwiched between the bus bar wiring 17 and the current collecting electrode 22. As shown in the figure, the spacer 15 is installed so as to protrude from the region M where the bus bar wiring 17 is located to the side regions P1 and P2. Although not essential, as shown in the figure, the spacer 15 may be disposed so as to partially overlap the back surface electrode 6 on the thin film solar cell element 10 adjacent to the element on which the current collecting electrode 22 is formed. Thereby, even if the bus bar wiring 17 is slightly displaced, it can be prevented from contacting the adjacent thin film solar cell element 10. In the drawing, a region Z indicates a peripheral portion of the translucent substrate 1. A film is not particularly formed in this region Z, and the substrate surface is exposed. A region N is a region where the thin film solar cell element 10 is formed and a region where the spacer 15 is not placed.

  Next, a sealing process is performed in which the sealing sheet 25 is heated and melted to adhere the back sheet 27 and the thin film solar cell 100. FIG. 9 is a cross-sectional view of the thin-film solar cell module according to Embodiment 1 completed after the sealing process, and is a cross-sectional view after the sealing step of FIG. In the sealing step, the laminator deaerates the space between the thin-film solar cell 100 and the sealing sheet 25 and the back sheet 27, and the sealing sheet 25 is softened or melted by high-temperature heating. 27 is attached on the thin film solar cell 100. A laminator is a device that, for example, sandwiches a module laminated with two diaphragm sheets and heats the diaphragm sheets while exhausting them with a vacuum pump. A typical heating temperature is 110-170 ° C. The sealing sheet 25 becomes a sealing adhesive layer 26 by deforming the sheet shape.

  The spacer 15 containing the thermoplastic resin material is also softened by heating in the sealing process, and the shape is deformed. The deformation is particularly large at the side surface. However, since the spacer 15 is previously sandwiched between the connection portions 13 of the bus bar wiring 17, the shape change is small, and it is isolated at a slight distance from the current collecting electrode 22 even after completion of the sealing process. Convex shape is maintained. Both surfaces of the bus bar wiring 17 of the connecting portion are sandwiched between the thermoplastic resin of the spacer 15 and the thermoplastic resin of the sealing sheet 25. The connection portion and the collecting electrode 22 are mainly bonded with the thermoplastic resin of the spacer 15.

  The shape of the connecting portion of the bus bar wiring 17 includes a flat portion T that is generally parallel to the surface of the current collecting electrode 22 between the connecting portions 13 and an inclined portion S that is inclined from the flat portion T to the connecting portion 13. The flat portion T is a portion where the spacer 15 is positioned below before the sealing step, and the inclined portion S is a portion where there is a gap between the side surface of the spacer 15 and the connection portion 13.

  In the inclined portion S, the deflection of the bus bar wiring 17 is concentrated in the gap portion by the step of connecting the collecting electrode 22 to the connecting portion 13 with a connecting material or the sealing step in which the sealing sheet 25 is pressed from the back. As shown in the figure, the cross section is curved into, for example, an S shape.

  In order to alleviate the stress generated between the current collecting electrode 22 and the bus bar wiring 17 due to the difference in thermal expansion, it is desirable that an inclined portion S having a particularly gently inclined angle can be formed. Further, it is desirable that the inclined portion S has a curved surface with a certain degree of slack. The flat portion T may also have some deflection and fine irregularities.

  Since the thermoplastic resin material of the spacer 15 heated and melted in the sealing step flows between the current collecting electrode 22 and the bus bar wiring 17 in the inclined portion S, it is possible to prevent the generation of a cavity in this portion. The effect is particularly remarkable when the wide bus bar wiring 17 is used. The inclined portion S may be filled with not only the resin material of the spacer 15 but also a part of the sealing adhesive layer 26.

  Moreover, FIG. 10 is sectional drawing of the thin film solar cell module of this Embodiment 1, and is sectional drawing after the sealing process of FIG. This figure corresponds to a cross-sectional view between X1 and X2 in FIG. In the figure, a region M is a region where the bus bar wiring 17 of the connecting portion is arranged. Regions P1 and P2 are side portions adjacent to the region M of the connecting portion. Region N is a portion of the thin-film solar cell element 10 located farther from the bus bar wiring 17 than the region P. The region N is relatively flat without the bus bar wiring 17 in the immediate vicinity.

  The vicinity of the side surface of the spacer 15 is greatly deformed by the sealing process, but since the spacer 15 protrudes to the regions P1 and P2 on the side of the connecting portion before the sealing process, the deformation is small at the connecting portion of the bus bar wiring 17. . Even if pressure is applied from the back sheet 27 side on the back during the sealing process, the bus bar wiring 17 is not easily deformed. In addition, in the region M of the connecting portion and the regions P1 and P2 on the side thereof, the thickness of the spacer 15 and the thickness of the sealing adhesive layer 26 made of the sealing sheet 25 are added, compared with the flat regions Z and N. A thick layer structure of thermoplastic resin is obtained. This thick layer structure is excellent in the effect of protecting the connecting part by dispersing the force received from the outside, and the connecting part is easily deformed inside when the thermal expansion difference between the board and the wiring is eased. Excellent. Further, since the thermoplastic resin only in the vicinity of the bus bar wiring 17 connection portion is locally thickened, it is more economical than a structure in which the thickness of the resin layer on the entire back surface of the solar cell is increased. Moreover, since the unevenness | corrugation was formed in the bus-bar wiring 17 by pinching | interposing the thin sheet-like spacer 15, even if it is long between the connection parts 13, a convex part with low height can be formed. For this reason, it becomes a thin module excellent in the stress relaxation effect.

  In the relatively flat region N and region Z, the thickness of the sealing adhesive layer 26 is approximately the same as the thickness of the resin sheet 25 before the sealing process. In the region M, since the connecting portion protrudes from the substrate side, the thickness of the sealing adhesive layer 26 may be slightly reduced. These changes in thickness can be adjusted by selecting the temperature and pressure of the sealing process and the material of the resin sheet 25 and the spacer 15.

  After the above-described sealing step, external wiring is attached to take out electric power to the outside to complete the thin film solar cell module. In the first embodiment, sealing is performed using a resin sheet 25 and a back sheet 27 in which an opening is formed, external wiring is connected to the lead wire 24 exposed in the opening, and the connection and the opening are connected. Seal with box 31. Note that the structure for taking out electric power to the outside is not limited to the first embodiment, and the opening and the connection box 31 are not necessarily used. Separate connection boxes 31 may be installed on the current collecting electrodes 21 and 22 of both electrodes.

  As described above, in the method of manufacturing the thin-film solar cell module according to the first embodiment, the plurality of thin-film solar cell elements 10 and the collector electrode 22 that extracts power to the outside are partially transmitted through the thin-film solar cell elements 10. A step of preparing a thin film solar cell 100 formed on the optical substrate 1 is provided. And the connection process which arrange | positions the bus-bar wiring 17 on the current collection electrode 22, and is electrically connected with the current collection electrode 22, and the sealing sheet 25 and the back sheet 27 on the thin film solar cell 100 and the bus-bar wiring 17 And a sealing step of covering and sealing with. The sealing sheet 25 is made of a thermoplastic resin. In the connecting step, the current collecting electrode 22 and the bus bar wiring 17 are electrically connected by a plurality of connecting portions 13 spaced apart from each other, and a spacer 15 containing a thermoplastic resin in the space between the current collecting electrode 22 and the current collecting electrode 22. It is installed between the bus bar wiring 17. In this sealing step, the collector electrode 22 and the bus bar wiring 17 are bonded together by a thermoplastic resin contained in the spacer 15 sandwiched between them.

  For this reason, the connection part excellent in the effect which relieve | moderates the stress by a thermal expansion difference can be easily manufactured in the bus-bar wiring 17 spaced apart from the current collection electrode 22. FIG. Even if the bus bar wiring 17 is a wide foil or thin plate, the resin is easily filled between the current collecting electrodes 22 and a cavity is not easily generated. If the cavities remain, moisture or the like tends to aggregate in the portions, and the current collecting electrode may be deteriorated quickly. However, in the present invention, since the cavities are not easily generated, a module with excellent long-term reliability can be realized.

  The spacer 15 does not necessarily have to be in the form of a sheet. However, if the connection portion 13 has a long distance of, for example, several centimeters or more, the current collecting electrode 22 and the bus bar wiring can be formed by forming a sheet as in the first embodiment. It becomes easy to create a connecting portion that is slightly separated from 17. For this reason, a thin module excellent in stress relaxation can be realized. The sheet shape is not limited to a plate shape without holes. For example, it may have a mesh shape in which fibers made of a thermoplastic resin can be knitted with a slight gap. Moreover, the surface does not need to be smooth, for example, the surface may be finely embossed.

  The electrical connection between the current collecting electrode 22 and the bus bar wiring 17 is made by using a material in which conductive particles are dispersed in an adhesive resin, and the thickness thereof is smaller than the thickness of the spacer 17. 17 can be easily fixed to the bus bar 17 and can easily form an uneven shape excellent in stress relaxation.

  Since the spacer 15 is effective as long as it is between the current collecting electrode 22 and the bus bar wiring 17, it is not essential to protrude to the side P 1 or P 2 of the bus bar wiring 17. A thing with a narrow width may be used. In the first embodiment, since the bus bar wiring 17 is installed so as to protrude from the sides P1 and P2, deformation of the side portion of the bus bar wiring 17 is prevented, and an uneven shape excellent in stress relaxation is obtained. Furthermore, since the spacers 15 are connected to each other at the portions protruding to the side of the bus bar wiring, a plurality of portions to be the spacers can be placed at a time, and the manufacture becomes easy.

  The spacer 15 can have various shapes. In the first embodiment, since the adjacent connecting portion 13 side has a side surface orthogonal to the extending direction of the bus bar wiring 17, an uneven shape is formed along the extending direction of the bus bar wiring 17. For this reason, it becomes a structure excellent in the stress relaxation of the extending direction.

  The sealing sheet 25 and the spacer 15 may be made of a different thermoplastic resin as a main component. If the thermoplastic resin contained in the sealing sheet 25 and the spacer 15 is made of the same quality, the substrate side and the back sheet side of the connecting portion of the bus bar wiring 17 are sandwiched between the thermoplastic resins having the same viscosity in the sealing process. An uneven shape that is prevented and has excellent stress relaxation is obtained. Further, it is more preferable because the thermoplastic resin of the spacer 15 and the thermoplastic resin of the sealing sheet 25 are integrated to eliminate the interface. EVA is preferable because of its excellent flexibility as such a thermoplastic resin.

  The solar cell module according to Embodiment 1 has a light-transmitting property including a plurality of thin-film solar cell elements 10 that are electrically connected to each other and a current collecting electrode 22 formed on a part of the thin-film solar cell elements 10. The thin film solar cell 100 which has on the board | substrate 1 is provided. A bus bar wiring 17 disposed on the current collecting electrode 22 and electrically connected to the current collecting electrode 22, a back sheet 27 covering the thin film solar cell 100 and the bus bar wiring 17, and the thin film solar cell 100 and the bus bar wiring 17 And the back sheet 27 are provided with a sealing adhesive layer 26 made of a thermoplastic resin. The bus bar wiring 17 is electrically connected to the current collecting electrode 22 through a plurality of connecting portions 13 spaced apart from each other. The connecting portion 13 has a connecting portion that is separated from the collector electrode 22 by a spacer 15 containing a thermoplastic resin, and the spacer 15 between the connecting portion and the collecting electrode 22 is located on the side of the connecting portion. It has the part which protrudes in P1 and P2. Thereby, the thickness of the thermoplastic resin layer between the back sheet 27 and the thin film solar cell 10 on the side portions P1 and P2 of the connecting portion becomes thicker than the sealing adhesive layer 26, and the effect of relieving the stress due to thermal expansion is reduced. Excellent.

  In the first embodiment, the configuration in which two bus bar wirings are formed on the back electrode is shown, but only one side may be used. One side may be in direct contact with the lower transparent electrode. As the spacer resin material, a thermoplastic resin such as EVA, which has superior elasticity after curing than a thermosetting resin such as epoxy resin, is used. Thermal expansion of bus bar wiring due to temperature changes in the use environment after completion Can also be flexibly deformed and relaxed, thus improving the service life and reliability.

<Embodiment 2. >
FIG. 11 is a cross-sectional view illustrating the manufacturing process of the thin film solar cell module according to the second embodiment, and is a diagram illustrating a portion corresponding to FIG. 7 of the first embodiment. The manufacturing process of the thin film solar cell module according to the second embodiment is basically the same as that of the first embodiment, but the bus bar wiring 17 installed in the region R above the spacer 15 above the connecting portion is finely formed in advance. It is different in that unevenness is formed. For this reason, in the completed module, since a fine unevenness | corrugation is made in the connection part spaced apart from the current collection electrode 22, the stress relaxation effect can be heightened. It is preferable that there are a plurality of fine irregularities as shown in the figure. The region R is not completely flat because of the fine irregularities, but is generally a flat portion parallel to the current collecting electrode 22. Further, the gap between the fine irregularities and the spacer 15 is filled with a thermoplastic resin contained in the spacer 15 in the sealing step.

<Embodiment 3. >
FIG. 12 is a cross-sectional view illustrating the manufacturing process of the thin film solar cell module according to the third embodiment, and is a diagram illustrating a portion corresponding to FIG. 7 of the first embodiment. The manufacturing process of the thin film solar cell module of the third embodiment is basically the same as that of the first embodiment, but the structure of the spacer 15 is different. The spacer 15 used in the third embodiment has a structure in which a first layer 15a and a third layer 15c made of a thermoplastic resin are sandwiched between the second layers 15b made of different materials. The material of the second layer 15b is a material whose melting point is higher than that of the thermoplastic resin of the first layer 15a and the third layer 15c. The material of the first layer 15 a and the third layer 15 c was the same thermoplastic resin material as that of the sealing sheet 25. For example, EVA having a melting point of about 100 ° C. may be used for the first layer 15a and the third layer 15c, and PET having a melting point of 200 ° C. or more may be used for the second layer 15b.

  FIG. 13 is a cross-sectional view illustrating the structure of the thin-film solar cell module according to the third embodiment after the sealing step, and is a diagram illustrating a portion corresponding to FIG. 10 according to the first embodiment. In the sealing process, the bus bar wiring 17 and the current collecting electrode 22 are bonded with the thermoplastic resin of the first layer 15a and the third layer 15c. Further, since there is the second layer 15b having a higher melting point than these, the shape change in the sealing process is reduced. For this reason, the effect which protects the shape of the connection part of the bus-bar wiring 17 increases. Further, the long-term reliability of the current collecting electrode 22 can be further increased by using a material having excellent moisture resistance for the second layer 15b.

<Embodiment 4. >
FIG. 14 is a diagram for explaining a manufacturing process of the thin-film solar cell module according to the fourth embodiment. FIG. 14 (a) is a top view of the bus bar wiring 17 used in the connection process as viewed from the substrate side. ) Is a cross-sectional view showing that the bus bar wiring 17 is installed and connected to the current collecting electrode 22. The manufacturing process of the thin-film solar cell module of the fourth embodiment is basically the same as that of the first embodiment, but a plurality of connection materials 12 are pasted on the current collecting electrode 22 side of the bus bar wiring 17 with a gap in advance. It differs in that it is attached. On the current collecting electrode 22, the spacer 15 is installed at a position where the connection portion 13 is to be formed. Thereafter, the bus bar wiring 17 is placed so that the connecting material 12 faces the collecting electrode 22 within the interval, and the bus bar wiring 17 is pressed in the direction of the white arrow to bring the connecting material 12 into contact with the collecting electrode 22. Connection portion 13. Since the bus bar wiring 17 to which the connecting material 12 is attached is used, productivity is improved.

  The connection material 12 is preferably a conductive material having adhesiveness, and a tape in which conductive particles are dispersed in a resin, an anisotropic conductive sheet, or the like is preferable. When the connection material 12 is brought into contact with the current collecting electrode 22, it is preferable to locally heat the contact portion because the adhesive force can be increased.

<Embodiment 5. >
FIG. 15 is a cross-sectional view for explaining a manufacturing process of the thin-film solar cell module according to the fifth embodiment, and shows the same process as that of FIG. 14B of the fourth embodiment. The manufacturing process of the thin film solar cell module of the fifth embodiment is basically the same as that of the fourth embodiment, but the connection material 12 of the bus bar wiring 17 is formed on the entire surface facing the current collecting electrode 22. The point is different. The connection material 12 may cover the entire surface of the bus bar wiring 17. The connection material 12 is, for example, a low melting point solder material. The position indicated by the white arrow is heated with a soldering iron while pressing the bus bar wiring 17, and the connecting material 12 is brought into contact with the current collecting electrode 22 to form the connecting portion 13. Since the bus bar wiring 17 to which the connecting material 12 is attached is used, productivity is improved. Since the spacer 15 is provided, it is possible to prevent the connecting portion from being fixed in contact with the current collecting electrode 22.

<Embodiment 6. >
FIG. 16 is a diagram for explaining a manufacturing process of the thin-film solar cell module according to the sixth embodiment. FIG. 16 (a) is a top view of the bus bar wiring 17 used in the connection process as viewed from the substrate side. ) Is a cross-sectional view showing that the bus bar wiring 17 is installed and connected to the current collecting electrode 22. The manufacturing process of the thin-film solar cell module of the sixth embodiment is basically the same as that of the fourth embodiment, but the spacer 15 in addition to the plurality of connecting materials 12 is provided on the current collecting electrode 22 side of the bus bar wiring 17. It is different in that is pasted. The connection material 12 and the spacer 15 are affixed alternately. Since the positions of the connection material 12 and the spacer 15 are determined, alignment is not necessary in the connection process, and work efficiency is further improved. Further, the spacer 15 can be easily installed even if there is no portion to be connected to each other, and a small amount of members are required. The region where the spacer 15 is affixed is also effective in the bus bar wiring 17, but it is more preferable that the spacer 15 protrudes from the side surface of the bus bar wiring 17 as shown in the figure.

<Embodiment 7. >
FIG. 17 is a diagram for explaining the connection process of the thin-film solar cell module according to the seventh embodiment. FIG. 17A is a top view of the bus bar wiring 17 used in the connection process as viewed from the substrate side, and FIG. ) Is a cross-sectional view showing that the bus bar wiring 17 is installed and connected to the current collecting electrode 22. The manufacturing process of the thin-film solar cell module of the seventh embodiment is basically the same as that of the fourth embodiment, except that a spacer 15 instead of a plurality of connection materials 12 is attached to the bus bar wiring 17. Different. The spacer 15 may have a structure divided along the bus bar wiring 17, but may be provided with a portion connected to the side surface of the bus bar wiring 17 as shown in the figure. After installing the plurality of connecting portions 13 on the current collecting electrode 22, the bus bar wiring 17 to which the spacers 15 are attached is placed, and the bus bar wiring 17 and the connecting portion 13 are connected. As in the fourth embodiment, work efficiency is good.

<Eighth embodiment. >
FIG. 18 is a diagram for explaining a connection process of the thin film solar cell module according to the eighth embodiment. FIG. 18A is a top view of the bus bar wiring 17 used in the connection process as viewed from the substrate side. ) Is a cross-sectional view showing that the bus bar wiring 17 is installed on the current collecting electrode 22, and FIG. 18C is a cross-sectional view showing a process of subsequently covering with the sealing sheet 25 and the back sheet 27. The manufacturing process of the thin-film solar cell module of the eighth embodiment is basically the same as that of the sixth embodiment, except that the pressing material 33 is installed on the opposite side of the plurality of connection materials 12 of the bus bar wiring 17. Is different. The thickness of the pressing member 33 is preferably the same as or slightly thicker than that of the spacer 15. The material of the pressing member 33 is preferably a material whose melting point is higher than that of the sealing sheet 25. Further, a material rich in elasticity is more preferable. For example, when the sealing sheet 25 is EVA having a melting point or a softening temperature of 100 ° C., the pressing member 33 is made of silicone rubber having a melting point of 200 ° C. or more. For this reason, the shape is maintained without being greatly deformed even after the sealing step. In addition, the position where the pressing member 33 is installed only needs to partially overlap the position on the opposite side of the connection material 12 of the bus bar wiring 17. As shown in the figure, the entire surface on the side opposite to the connection material 12 may be covered and further protruded to the side of the bus bar wiring 17. However, the installation position of the pressing member 33 is set so as not to overlap the opposite side of the spacer 15.

  The bus bar wiring 17 as described above is installed on the current collecting electrode 22. Next, as shown in FIG. 18C, the sealing sheet 25 and the back sheet 27 are covered and sealed. In this sealing step, the pressing material 33 is pressed from the back sheet 27 side, whereby the bus bar wiring 17 is deformed so as to be uneven, and the connecting material 12 is in contact with the current collecting electrode 22 by the pressing material 33. 13 Since the connecting step and the sealing step can be performed at the same time, workability is excellent.

  As described above, in the thin film solar cell module according to the eighth embodiment, the pressing member 33 that presses the bus bar wiring 17 at the position of the connecting portion 13 toward the current collecting electrode 22 is installed between the bus bar wiring 17 and the back sheet 27. Yes. For this reason, since the adhesive force of the connection part 13 becomes strong and peeling of the connection part 13 can be prevented, it becomes a highly reliable module. For example, when tensile stress is generated in the bus bar wiring 17 due to a difference in thermal expansion due to a low temperature in the usage environment, the effect of preventing the connection portion 13 from peeling off is remarkable. In addition, after installing the bus bar wiring 17 on the current collecting electrode 22, the connecting portion 13 may be formed by pressing the pressing member 33 before the sealing step. Further, although the pressing material 33 bonded in advance to the bus bar wiring 17 is used, the pressing material 33 is placed on the position to become the connecting portion 13 before or after the process of connecting the bus bar wiring 17 and the current collecting electrode 22. However, a highly reliable module can be realized.

<Embodiment 9. >
FIG. 19A is a top view for explaining the manufacturing process of the thin-film solar cell module according to Embodiment 9, and FIG. 19B is a cross-sectional view showing the structure completed through the process. The manufacturing process of the thin-film solar cell module of the ninth embodiment is basically the same as that of the first embodiment, except that a slit U is formed in the spacer 15 between the adjacent connecting portions 13. FIG. 19A corresponds to FIG. 5A of the first embodiment, and FIG. 19B corresponds to FIG. 9 of the first embodiment. FIG. 19A shows the case where one slit U is provided in the spacer 15 between the connecting portions 13, but a plurality of slits U may be provided therebetween. Further, the slit U may be a groove that does not penetrate the spacer 15.

  The portion of the slit U of the spacer 15 is a portion where the resin layer becomes thin in the sealing process. For this reason, the bus bar wiring 17 thereon is deformed as in the region V. Without forming irregularities in advance, it is possible to create irregularities with an excellent stress relaxation effect at the connecting portion in the sealing step. If the width of the slit U is too large relative to the thickness of the spacer 15, the slit U is deformed so as to be in contact with the current collecting electrode 22 in the sealing process, and the stress relaxation effect is reduced or the current collecting electrode 22 is damaged. There is a possibility. In order to prevent this, the width of the slit U should be 5 times or less, preferably 2 times or less the thickness of the spacer 15.

<Embodiment 10. >
FIG. 20A and FIG. 20B are top views for explaining the manufacturing process of the thin-film solar cell module according to the tenth embodiment. The manufacturing process of the thin film solar cell module of the tenth embodiment is basically the same as that of the first embodiment, but the shape of the spacer 15 is different. In the first embodiment, the spacers 15 are connected to each other at a portion protruding from one side of the bus bar wiring 17, but in the tenth embodiment, the spacers 15 are connected to each other at a portion protruding from both sides. Shaped. FIG. 20A shows a case in which the portions protruding to both sides of the spacer 15 are all continuously connected to have a ladder shape as a whole. The connecting member 11 is located in a ladder-shaped gap. FIG. 20B shows a case where the shape is different from that shown in FIG. 20A, in which the protruding portions on both sides of the spacer 15 are alternately and continuously connected to have a meandering shape as a whole. The effect similar to that of the first embodiment can be obtained even with such a shape of the spacer 15.

  Although the embodiment of the present invention has been described above, the specific configuration of the present invention is not limited to the present embodiment, and even if there is a design change or the like without departing from the gist of the invention, Included in the invention. In addition, a part of the structures described in the above embodiments may be combined with or replaced with the structures described in the other embodiments as long as no significant technical inconvenience occurs. Moreover, when an effect is acquired only with the part of the structure, you may utilize only the partial structure.

  ADVANTAGE OF THE INVENTION According to this invention, the solar cell module excellent in the effect which relieve | moderates the stress which generate | occur | produces by thermal expansion is realizable.

DESCRIPTION OF SYMBOLS 1 Translucent board | substrate, 2 Transparent electrode, 4 Photoelectric conversion layer, 6 Back surface electrode, 10 Thin film solar cell element, 12 Connection material, 13 Connection part, 15 Spacer, 17 Busbar wiring, 21, 22 Current collection electrode, 23 Lead wire , 24 resin sheet, 25 sealing sheet, 26 sealing adhesive layer, 27 back sheet, 31 connection box, 33 pressing material, 100 thin film solar cell.

Claims (12)

Preparing a thin-film solar cell in which a plurality of thin-film solar cell elements and a collecting electrode for extracting power to the outside of a part of the thin-film solar cell elements are formed on a light-transmitting substrate;
A connecting step of arranging a bus bar wiring on the current collecting electrode and electrically connecting to the current collecting electrode;
A sealing step of covering and sealing the thin film solar cell and the bus bar wiring with a sealing sheet and a back sheet made of a thermoplastic resin,
In the connecting step, the current collecting electrode and the bus bar wiring are electrically connected by a plurality of connecting portions spaced from each other, and a spacer containing a thermoplastic resin in the space region includes the current collecting electrode and the current collecting electrode. A method for manufacturing a thin-film solar cell module installed between bus bar wirings. The method for manufacturing a thin-film solar cell module according to claim 1, wherein the spacer has a sheet shape. The electrical connection between the current collecting electrode and the bus bar wiring is made of a material in which conductive particles are dispersed in an adhesive resin, and the thickness of the material is smaller than the thickness of the spacer. Manufacturing method of thin film solar cell module. 4. The method of manufacturing a thin-film solar cell module according to claim 1, wherein, in the connecting step, the spacer is installed so as to protrude from between the current collecting electrode and the bus bar wiring to a side of the bus bar wiring. . The method of manufacturing a thin-film solar cell module according to claim 4, wherein the spacers are connected to each other at a portion protruding to the side of the bus bar wiring. The method of manufacturing a thin-film solar cell module according to claim 1, wherein the spacer has a side surface orthogonal to an extending direction of the bus bar wiring on an adjacent connection portion side. The method for manufacturing a thin-film solar cell module according to claim 1, wherein the bus bar wiring on the spacer has an uneven portion. The method for producing a thin-film solar cell module according to any one of claims 1 to 7, wherein the thermoplastic resin contained in the sealing sheet and the spacer is the same. The method of manufacturing a thin film solar cell module according to claim 8, wherein the homogeneous thermoplastic resin is EVA. The method for producing a thin-film solar cell module according to any one of claims 1 to 9, wherein a layer made of a material having a melting point higher than that of the thermoplastic resin of the sealing adhesive layer is sandwiched between the spacers. A thin film solar cell having a plurality of thin film solar cell elements electrically connected to each other and a collecting electrode formed on a part of the thin film solar cell element on a light-transmitting substrate;
A bus bar wiring disposed on the current collecting electrode and electrically connected to the current collecting electrode;
A backsheet covering the thin-film solar cell and the bus bar wiring;
A sealing adhesive layer made of a thermoplastic resin between the thin film solar cell and the bus bar wiring and the back sheet, and
The bus bar wiring is electrically connected to the current collecting electrode at a plurality of connection portions spaced from each other, and the connection between the current collecting electrodes is separated by a spacer containing a thermoplastic resin between the connection portions. Part
The thin film solar cell module, wherein the spacer between the connecting portion and the collecting electrode has a portion protruding to the side of the connecting portion. The thin film solar cell module according to claim 11, wherein a pressing member that presses the bus bar wiring at the position of the connecting portion toward the current collecting electrode is disposed between the bus bar wiring and the back sheet.

Images